The Amundsen-Scott South Pole Station made headlines in April when the doctor for that remote science facility was taken seriously ill in the middle of the dark, frigid Antarctic winter. Thankfully, Canadian pilots successfully evacuated the stricken physician—but he was not all that was ailing at the bottom of the world. The station itself has been deteriorating for years, prompting the National Science Foundation to begin this past year a $153 million modernization, which should be completed by early 2006. (66) But construction at this remote site is no small task. All materials have to be carried in by air from McMurdo Station on the coast using special ski-equipped transport planes. And workers have to contend with temperatures that average around -32 degrees Celsius over the summer months. (67) The South Pole also provides astrophysicists with a remarkable laboratory to study high-energy neutrinos: AMANDA (Antarctic Muon and Neutrino Detector Array) uses deeply buried
A. One such place is Dome C (located in the Australian sector, at roughly 73 degrees South latitude), where French and Italian scientists are now setting up a permanent base, called Concordia Station.
B. The logistical difficulties and great expense prompt one to ask. Why maintain a permanent science base at the South Pole at all One answer is that certain kinds of research can be done in no other spot. In particular, the South Pole is said to offer an ideal setting for astronomers, because the air is exceptionally cold, thin and dry, making this locale the next best place for sitting a telescope.
C. European and Australian astronomers are indeed quite interested in the opportunities that Dome C affords. Still, U.S. participation will probably not amount to much, because, as Bally notes, "the U.S. has put all its eggs in the South Pole." This strategy is hard to defend on the basis of doing the best astronomy, the discipline most often cited in official statements about the scientific importance of Amundsen-Scott Station.
D. The submillimeter to millimeter-scale observations are, however, critical to the study of the cosmic microwave background radiation, and they are useful, too, for examining molecular clouds in stellar nurseries.
E. Also, the air at the South Pole is, in fact, not so perfect for astronomy, because it is colder at the surface than a few hundred meters above. John Bally, an astronomer now at the University of Colorado, Boulder, who was responsible for site testing at the South Pole, points out that this temperature inversion combined with the stiff winds there give rise to a turbulent layer of air that blurs optical and infrared images. Bally also notes that there is a perpetual ice fog at the South Pole in winter and that the base is situated on the auroral circle, the locus where charged particles in the upper atmosphere light up the sky most intensely: "You would not go about picking astronomical sites the way this was done."
F. Built in the 1970s to replace an even older South Pole base (which is now buried under nine meters of snow), the Amundsen-Scott Station consists of a large geodesic dome and several smaller outbuildings. The dome is half-buried in drifts and suffers from an unstable foundation that threatens its integrity. Many other parts of the infrastructure—from fuel distribution to waste disposal—are also in dire need of refurbishment.
If you think you have a puncture (漏气), first check the valve (阀门) to make sure air is not leaking from it, by putting spit on the end of it. If the valve is not the source of the leak, remove the wheel from the bicycle and take the tyre off. Be careful not to pinch(挤、扎) the inner tube. Remove the inner tube and pump some air into it. Then hold it in a bowl of water until you see bubbles (气泡) coming from it. Or, hold the tube to your ear and listen for air escaping. Dry the tube. Choose a patch that is big enough to cover the hole and the surrounding area. Apply glue to the tube before sticking patch down. Before you put the tube back in the tyre, run your fingers over both the inside and outside of the tyre to make sure that whatever caused the puncture is not still there. To replace the tube, put the valve part way through the hole in the rim (轮圈), pump a little air in, and then feed it carefully under the tyre. Push the tyre over the rim and back into position. Do not u
A. push the tyre back into position
B. take out the inner tube
C. remove the wheel from the bike
D. replace the wheel on the bike
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